Close revoked remote sessions and document installation requirements

MusicBridgeRemote/MusicBridgeRemote.swift

@@ -45,7 +45,8 @@ final class PCMediaSession: RemoteMediaSessionRepresentable {
     }
 
     var commands: [MediaCommand] {
-        [
+        guard attributes.hasSession else { return [] }
+        return [
             .play { try await self.send(.play) }.enabled(attributes.capabilities.play),
             .pause { try await self.send(.pause) }.enabled(attributes.capabilities.pause),
             .next { try await self.send(.next) }.enabled(attributes.capabilities.next),
@@ -62,7 +63,15 @@ final class PCMediaSession: RemoteMediaSessionRepresentable {
     }
 
     private func send(_ action: SystemPlayerAction, value: Double? = nil) async throws {
-        let state = try await transport.send(action, value: value, sessionID: id)
-        attributes = SystemPlayerAttributes(id: id, state: state)
+        do {
+            let state = try await transport.send(action, value: value, sessionID: id)
+            attributes = SystemPlayerAttributes(id: id, state: state)
+        } catch BridgeError.unauthorized {
+            try SystemPlayerCredentials.delete(id)
+            attributes.hasSession = false
+            attributes.playing = false
+            attributes.volume = nil
+            throw BridgeError.unauthorized
+        }
     }
 }